Selector-Label Volume Binding

Overview

This guide provides the steps necessary to enable binding of persistent volume
claims (PVCs) to persistent volumes (PVs) via selector and label attributes.
By implementing selectors and labels, regular users are able to target
provisioned
storage by identifiers defined by a cluster administrator.

Motivation

In cases of statically provisioned storage, developers seeking persistent
storage are required to know a handful identifying attributes of a PV in order
to deploy and bind a PVC. This creates several problematic situations. Regular
users might have to contact a cluster administrator to either deploy the PVC or
provide the PV values. PV attributes alone do not convey the intended use of the
storage volumes, nor do they provide methods by which volumes can be grouped.

Selector and label attributes can be used to abstract away PV details from the
user while providing cluster administrators a way of identifying volumes by a
descriptive and customizable tag. Through the selector-label method of binding,
users are only required to know which labels are defined by the administrator.

The selector-label feature is currently only available for statically provisioned
storage and is currently not implemented for storage provisioned dynamically.